1. Field of the Invention
This invention relates to a process for producing a fibrous or meat-like food product by treatment of a vegetable protein containing seed meal material under controlled conditions of heat, pressure and pH.
2. Description of the Prior Art
The prior art disclosed that fibrous meat-like products are produced from soy protein by forming an alkaline solution of soy protein from a defatted, dehulled soybean meal or grit. The alkaline soy protein solution is then commonly extruded from spinnerettes into a coagulating bath containing salt and having a pH on the acid side. The fibers formed by this procedure are frequently accumulated into a tow and the tows combined to make a larger unit. The fibers in this tow are customarily oriented in the same direction to simulate the normal fiber and grain texture of meat. The tows may be impregnated with fats, spices, other proteins, flavors, etc. Frequently, they are then cooked and cut. One of the problems associated with the use of regenerated soy protein is that the use of strongly alkaline solutions in the process results in hydrolysis and loss of some protein and the final product is characterized by a lowered food protein efficiency ratio.
The prior art also discloses the treatment of soybean meal to remove odors by contacting a dehulled, defatted soybean meal with certain protonic acids, limited amounts of moisture (water), low temperatures and short periods of time. (See U.S. Pat. No. 3,361,574).
It is also known to produce soybean based food products which are essentially cellular or expanded in character. These products are obtained by a variety of processes which include as a principal step the heating of a soybean based dough containing moisture at elevated temperatures and pressures followed by the sudden release of pressure which permits trapped moisture in the product then under pressure, to expand and produce numerous elongated cells which are oriented in the product. The final product may be characterized as popped or exploded. (See Atkinson U.S. Pat. No. 3,488,770).